1. Field of the Invention
The present invention involves an alkylated hydroxyaromatic compound, derived from a conventional polyisobutylene and a high vinylidene polyisobutylene, and a process to prepare the alkylated hydroxyaromatic compound. Additive, concentrate and fuel compositions as well as a method that effectively reduces deposit formation in a fuel system of an internal combustion engine comprise a Mannich reaction product that is prepared from the alkylated hydroxyaromatic compound.
2. Description of the Related Art
Both conventional polyisobutylene and high vinylidene polyisobutylene are available commercially as a starting material to alkylate hydroxyaromatic compounds such as phenols. The alkylated hydroxyaromatic compounds can be used as functional additives and as intermediates to functional additives for various applications. Conventional polyisobutylenes are generally prepared by polymerizing isobutylene or an isobutylene containing composition, such as a C4 hydrocarbon stream from a petroleum catalytic cracker, with an active acidic polymerization catalyst such as AlCl3. The resulting conventional polyisobutylene (PIB) can contain mainly about 60 to 70 mole % of a trisubstituted double bond isomer (—CH2C(CH3)═CHCH3) and lesser amounts of about 20 to 25 mole % of a tetrasubstituted double bond isomer (—CH(CH3)—C(CH3)═C(CH3)2) and about 5 to 20 mole % of alpha- and/or beta-vinylidene double bond isomers. High vinylidene polyisobutylenes are usually prepared by polymerizing isobutylene or an isobutylene containing composition with a milder acidic polymerization catalyst such as BF3. The resulting high vinylidene PIB can contain about 90 mole % or greater of alpha- and/or beta-vinylidene double bond isomers (respectively —CH2C(CH3)═CH2 and/or —CH═C(CH3)2) and a minor amount of other isomers including about 1 to 10 mole % of a tetrasubstituted double bond isomer. High vinylidene PIBs because of their double bond makeup are generally thought to be more reactive and to provide derivatives such as alkylated phenols and derivatives of alkylated phenols that are more effective as functional additives when compared to conventional PIBs and derivatives thereof.
Cherpeck in European Publication No. EP 628022B1 discloses a process for alkylating a hydroxyaromatic compound with a PIB having a methylvinylidene isomer content of at least 70%.
Kolp in U.S. Pat. No. 5,663,457 discloses that conventional low vinylidene polyolefins are condensed with hydroxyaromatics under influence of macroreticular ion exchange resins in acid form to yield alkylated hydroxyaromatics.
Moreton in U.S. Pat. No. 5,876,468 discloses a Mannich reaction product that shows good detergency performance in hydrocarbon fuels where the Mannich reaction product is prepared from a PIB-substituted phenol, an aldehyde and ethylenediamine where the PIB has at least 70% vinylidene double bond isomer.
Lange et al. in International Publication No. WO 01/25294A1 disclose a method for producing a Mannich adduct from a phenol that is alkylated with a PIB having more than 70 mole % vinylidene double bonds as well as compositions and uses that employ the Mannich adduct.
Lange et al. in International Publication No. WO 02/26840A2 disclose a method for producing polyisobutenylphenols from a polyisobutylene containing at least 35 mole % of a double bond in the position beta.
It has now been found that a derivative of an alkylated hydroxyaromatic compound derived from a conventional PIB and a high vinylidene PIB is unexpectedly equally effective to more effective as a fuel additive than a derivative of an alkylated hydroxyaromatic compound derived from a high vinylidene PIB. This discovery is advantageous in that it provides fuel marketers with a new high performance fuel additive and that it provides manufacturers of conventional PIB with a new use for their product. Additional advantages of an alkylated hydroxyaromatic compound and derivatives thereof derived from a conventional PIB, usually prepared from a chlorine containing catalyst, and a high vinylidene PIB are reduced raw material cost due to the less expensive conventional PIB and alkylates and derivatives thereof that can meet low chlorine requirements.